BGS - 06. Graphs and Averages

Question 1

Averages

The mean of a group of numbers is the sum of the numbers divided by how many numbers there are.

What is the mean of;

13, 3, 14, 2, 24.5, 12.5

Answer 1

13 + 3 + 14 + 2 + 24.5 + 12.5
= 69
69 / 6

11.5

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Question 2

Median

The median is the middle number of a group of numbers. To calculate the median you need to put the list in order.

If there is an odd number of numbers, the middle number is the median.

If there are an even number of numbers, the median is the mean of the two middle numbers

Find the median of;

37, 28, 46, 24, 12

Answer 2

37, 28, 46, 24, 12
Put them in order;
12, 24, 28, 46, 37
Median = 28

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Question 3

Median

When there is a long list of numbers, once putting the numbers in order, you can find the middle number by counting how many numbers there are, deduct 1, divide by 2, and then add 1 back.
Whatever the answer is, you count from the left to find the middle number

Answer 3

37, 28, 46, 24, 12
Put them in order;
12, 24, 28, 46, 37

There are 5 numbers.
5 -1 = 4
4 divided by 2
4 / 2 = 2
2 add 1
2 + 1 = 3
Count 3 from the left, the 3rd number is the median

28

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Question 4

Mode

The mode is the number which occurs the most often in a data set.

There can be more than one mode for a data set.

What is the mode of;

15, 14, 14, 15, 16, 14, 12, 19, 17, 12, 15, 18, 19, 17, 12, 15, 13, 14

Answer 4

Count the number of occurrances

3 = 12
1 = 13
4 = 14
4 = 15
1 = 16
2 = 17
1 = 18
2 = 19

Mode = 14 and 15

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Question 5

Range

The range is the difference between the highest and lowest numbers.

What is the range for;

6, 6, 7, 7, 8, 8, 8, 9, 9, 10, 10

Answer 5

10 - 6 = 4

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Question 6

Mean, Median, Mode

Way to remember;

Median = ‘Meed’le as in “middle”

Mode = ‘Mo’st offen